United States Patent Application 20020025915 A1, Franklin et al., par. 0025, states, in part: “Triester formation in the esteramine mixture can be minimized by accelerating the heat up rate in the esterification reaction of fatty acids with alkanolamines. Typically, the accelerated heat up rate of greater than about 0.4° C. per minute, more preferably greater than about 0.8° C. per minute, and still more preferably greater than about 1.25° C. per minute from a temperature of about 70° C. to a temperature in a range of from between 170° C. to 250° C. is effective in minimizing triester formation in the esteramine mixture.” Franklin et al. further states in part at par. 0035: “The quaternary ammonium compounds according to the present invention can generally be prepared by reacting at least one C12-C22 fatty acid having a IV of from 20-90 with an alkanol amine in the presence of an acid catalyst. * * * A heat up rate of at least about 0.8° C. per minute is employed in order to minimize triester formation. The esterification products are subsequently alkylated in order to obtain the quaternary ammonium product.” The Franklin et al., published patent application is hereby incorporated herein by reference in its entirety for its disclosure of quat esters of tri(lower alkanol) amines such as triethanolamine and fatty acid sources, formulations containing such quat esters and optionally other ingredients, and methods for making such quat esters of triethanolamine and fatty acid sources.
EP 0 675 941, also published as WO94/14935, and WO 91/01295, are also pertinent here, and are incorporated here by reference in their entireties for their disclosure of quat esters of tri(lower alkanol) amines such as triethanolamine and fatty acid sources, formulations containing such quat esters and optionally other ingredients, and methods for making such quat esters of triethanolamine and fatty acid sources.
Esterquat products have been made outside the United States for many years by various producers, including Stepan Company, using ramp up rates below the rates required by the Franklin et al. published application.